The invention relates to a centrifugal pump assembly with a device for separating gas from the fluid to be delivered.
Centrifugal pump assemblies of the previously mentioned type are typically applied in heating installations as circulation pumps, but also on other fields. Even if such systems are typically designed in a pressure-tight manner, one may often not prevent the circulated fluid from entraining gas, in particular air, which is to be separated away from the system, usefully before running through the centrifugal pump. The provision of gas separation devices in such systems is therefore counted as belonging to the state of the art.
With an increasing integration of systems, one has gone over to integrating such a gas separation device in the centrifugal pump assembly (DE 199 20 780 A1), typically on the suction side between the suction stub and the entry to the pump, the suction port. Thereby, the extension of the pump housing on the suction side and dividing it via a so-called deflector plate which has a central opening, in order to form a separation space, into which the fluid flowing in on the suction side firstly enters and the flow speed slows down, before it is again withdrawn centrally to the suction port of the pump, is counted as belonging to the state of the art. A so-called air vent which comprises a bleed valve, with which the gas separated from the delivery fluid is automatically led away to the environment, connects to this calming space in the installation position on the upper side. In order to prevent a turbulent or other rapid fluid flow in the region of this air vent, which would compromise the separation procedure, thus the separation of the gas and fluid, a guidance device is typically provided on the deflector plate, and this device shields this region of the calming space from the remaining flow.
The disadvantage with this known design, is on the one hand that the gas separation is often not adequate, and on the other hand that the guidance device which is attached on the deflector plate must be aligned in an exact manner on assembly, so that it is located at the predefined location within the housing.